This invention relates generally to fireworks and, more particularly, to an aerial fireworks product comprising an upstanding launch tube and a self-propelled aerial device that is adapted to be inserted into and launched from the tube. More specifically, the invention relates to improvements in the stabilizing base that forms an important part of the aerial device.
My co-pending application Ser. No. 09/482,579 filed Jan. 13, 2000 now U.S. Pat. No. 6,586,112B6 titled xe2x80x9cAerial Fireworks Productxe2x80x9d discloses a self-propelled aerial device launched from within an upright launching tube. The body of the device includes a packet of incendiary materials that produce a pyrotechnic display when ignited during flight, as well as an engine for propelling the device skyward. Three wooden legs project down from the body to serve as a means of stabilizing the device during flight, and also as a means of standing the device upright within the launch tube prior to ignition.
The stabilizer is a critical component of the device. For example, if all parts of the stabilizer are not substantially symmetrical with the center line of symmetry of the body and engine, the device may fly in an errant or unpredictable manner, rather than straight up vertically as intended. Achieving such a high level of symmetry with wooden sticks or legs as the stabilizing means is problematic because, for one thing, the sticks tend to warp out of a perfectly straight configuration over time, thus displacing their center of gravity off to one side. Moreover, some portions of the wooden stick tend to retain different amounts of moisture than other portions, causing weight distribution problems between the multiplicity of sticks.
Accordingly, an important object of the present invention is to provide an improved stabilizing base for a self-propelled aerial pyrotechnic device that addresses problems associated with my previous stabilizing means. In this respect, the present invention provides a stabilizer in the nature of a framework having a plurality of longitudinally extending legs spaced about the axis of symmetry of the device and transverse strut structure that interconnects the legs in a manner to retain them against significant displacement out of a symmetrical relationship. In a preferred form of the invention, three legs are provided so as to form corners of a triangle when the framework is viewed in transverse cross section, thus providing a sturdy, essentially rigid framework. In a further form of the invention, the framework is constructed of integrally molded synthetic resinous material to facilitate manufacture and to eliminate the problems with moisture retention in my earlier stabilizing legs.
The framework presents an elongated, open socket at its upper end into which the engine of the body is inserted during manufacture of the device. Preferably, a suitable adhesive between the engine and interior surfaces of the legs of the framework is used to bond the body of the device to the framework. The strut structure of the framework includes not only an annular ring that covers and interconnects the upper ends of the legs, but also a pair of generally triangular in plan strut units at two locations below the ring. The upper strut unit serves also as a limit stop for engaging the bottom extremity of the engine during assembly of the product at the factory, thereby establishing the maximum extent to which the engine can be inserted into the socket of the framework. A nib-like projection or button extending from the bottom of the framework keeps the framework from being self-supporting if attempts are made to stand the device upright outside of the launch tube, causing the device to tip over.